https://www.theverge.com/circuitbreaker/2018/2/8/16990480/apple-homepod-orders-sell-out

It’s unusual for a major new Apple product not to sell out on day one, and it seems that the HomePod isn’t going to buck the trend. Order estimates in the US slipped overnight from delivery tomorrow — launch day — to next Tuesday, meaning that if you haven’t placed a HomePod order yet, you probably won’t be able to get one from Apple on day one. The smart speaker appears to be sold out for in-store pickup as well, though it’s possible some units are reserved for walk-in customers. The speaker does, however, remain available through third-party retailers.

While selling out is the norm for a major Apple product, it’s not the norm for a product to only sell out on the final day of preorders, rather than just a few days after they begin. In this case, people seem to have waited for reviews to drop before making a purchase, perhaps because there were a lot of open questions about how the speaker will work — and few people had ever even heard it. But after reviews went up on Tuesday, and reviewers largely praised its sound quality, interested customers may have been more inclined to place an order.